Screening for Breast Cancer Information For Primary Care Providers in Michigan

Renee W. Pinsky, MD Assistant Professor

Department of Radiology University of Michigan Health System

Screening Mammography •  Module 4: Agreement over screening

–  Screening Mammography reduces breast cancer mortality •  Module 5: Controversies in screening

–  When to start? –  When to end? –  How often?

•  Module 6: Negative consequences of screening

Module 4 Agreement over screening

•  Intended Learning Outcomes –  Be familiar with the extensive research demonstrating

mortality reduction resulting from screening mammography

–  Counsel patients regarding the utility of mammography including evidence for mortality and morbidity reduction

Agreement over Screening

•  Outline: –  Screening mammography introduction –  Breast Cancer (BC) mortality rates –  Scientific support of screening mammography

•  RCT •  Observational studies •  Computerized models

Screening Mammography in Average Risk Women

•  Purpose: –  To decrease mortality and morbidity from breast cancer

(BC) •  To detect cancers at an earlier stage than when clinically

apparent •  To allow more limited surgery and medical treatment

•  Asymptomatic women

ACS 2014, SEER 2015

Declining USA Female Breast Ca Mortality Rate

ê2 % / year 1990-2011 = 35%

Screening and Treatment Greater decline if Mortality trend used

Randomized Controlled Trials (RCT) •  1970s-1990s-old studies •  Invitation not as treated •  Allowed screening in control arm (contamination) •  Variable mammogram methodologies:

–  Age range –  Frequency of screening 12,18, 24 month intervals –  Number of rounds of screening –  Length of follow up

Smith RA. The randomized trials of breast cancer screening: What have we learned? Radiol Clinics of NA 2004

Marmot MG et al, The benefits and harms of breast cancer screening: an independent review. British Journal of Cancer (2013) 108, 2205–2240

RCT: RR= 0.80 (0.73-0.89) UK Review

RCT Long Term Follow Up Studies Swedish Two County Trial

•  29 years •  RR of BC death 0.69= 31% mortality reduction •  Most prevented deaths occurred after 10 years of follow up

Tabár, L et al, Swedish Two-County Trial: Impact of Mammographic Screening on Breast Cancer Mortality during 3 Decades Radiology 2011 260:3, 658-663

Invited

Not invited

Canadian National Trial –  Original study:

•  Mammography did NOT reduce BC mortality •  Ages 40-59 •  Outlier from other RCTs

–  25 year follow up •  Mammography did NOT reduce BC mortality

Miller AB et al Twenty five year follow up for breast cancer incidence and mortality of the Canadian National Breast Screening Study: randomized screening trial. Br. Med. Journal 2014 Feb 11:348

10 observational studies: Meta-analysis 49% Mortality Reduction

Nickson C et al. Cancer Epidemiol Biomarkers Prev 2012 ;21:1479-1488 ©2012 by American Association for Cancer Research

•  40% MORTALITY REDUCTION –  ~2.8 million screening studies –  Age 40-79 –  All age decades similar (40s-70s)

Coldman A et al Pan-Canadian Study of Mammography Screening and Mortality Image from Breast Cancer JNCI (2014)106 (11)

Biennial 50-74 (USPSTF) vs Annual 40-84 (ACS, NCCN)

(mean 6 CISNET models)

LYG/1000

Mortality Reduction (%)

B 50-74

110

23

A 40-84

189

40

Difference(%) 79 (72% ) 16.3 (71% ) Hendrick and Helvie, AJR 2011 Derived from: Mandelblatt J S et al. Ann Intern Med 2009;151:738-747

Screening vs. treatment effect

46% mortality reduction attributed to

mammography

Low screening compliance (< 50%)

Berry DA, Effect of screening and adjuvant therapy on mortality from breast cancer. N Engl J Med 2005;353(17) 1784-92

Screen impact at 100% relative to SCR +TX Model S 74% due to annual screen (39.0% of 52.5%) Model E 69% due to annual screen (35.6% of 51.8%)

Munoz D et al, Effects of Screening and Systemic Adjuvant Therapy on ER-specific US Breast Cancer Mortality JNCI Vol. 106, Nov 2014

Morbidity: Age 40-79, British Columbia

46% less Chemotherapy among screened 47% higher use of BCT among screened

Coldman AJ,et al. A retrospective study of the effect of participation in screening mammography on the use of chemotherapy and breast conserving therapy, Int J Cancer: 120, 2185-2190 (2007)

Decreased Morbidity Screen vs Palpable Detection

Age 40-49

Screened Symptoms Mastectomy 25% 47%

Chemotherapy 45% 81%

Malmgren J A et al. Impact of mammography detection on the course of breast cancer in women aged 40-49 years. Radiology 2012 ;262:797-806